For backlights of illuminating devices and liquid crystal displays, a white light source configured of a light emitting diode is used. As such white light source, there has been known a white light source in which a cerium-containing yttrium aluminum garnet (hereinafter, referred to as YAG:Ce) phosphor is arranged on the luminescence surface side of a blue light-emitting diode (hereinafter, referred to as a blue LED).
In addition to this, there has been known a white light source in which green and red sulfide phosphors are arranged on the luminescence surface side of a blue LED (For example, refer to PTL 1). Furthermore, there has been known a configuration of a white light source in which, on the luminescence surface side of a LED which emits light in blue-violet or blue, a phosphor substance obtained by solid-dissolving Mn, Eu, and the like into a CaAlSiN3 crystal is arranged with another phosphor substance in combination at a specified proportion (For example, refer to PTL 2).